Cellular In vivo Imaging

Division Of Basic Sciences - Nci

Investigators

Linked publications, trials & patents

Abstract

Over the past year our team has made progress in the field of cell tracking. 1. Direct cell labeling with Zr-89. This technique allows cells to labeled outside the body and then be re-injected. We completed work in understanding where the Zr-89 oxine binds within the cell. Most of the binding takes place in the cytoplasm. We also completed a number of studies that detail the fate of monocytes and macrophages once they are transferred back into the donor. Monocytes are seen to get into tumors and sites of inflammation whereas macrophages are blocked from entry into tumors but can be seen in regions of acute injury. Interestingly, monocytes that traffic into tumors can be later converted to macrophages. Next year the GMP radiopharmacy will open allowing Zr-89 oxine labeling of human cells and re-injection into human donors. This will have profound implications for improving cell based therapies and engineering cells to specifically traffic to cancer sites. 2. Indirect or reporter gene strategies. We continue to make progress in showing that genetically engineered cells can be changed to allow a reporter gene to bind enabling tracking of those cells over long time periods. This can be accomplished by simply re-injecting the reporter at relevant times. Working with Dr. Dunbar's lab we have produced amazing images of mesenchymal stem cells injected into the heart wall of non human primates. The cells that implant in the wall can be imaged as discrete areas of viable cells that eventually form normal heart muscle. It is clear that the reporter gene strategy will be a powerful tool in improving cell based therapies especially in regenerative medicine and in stem cell therapies.